Echos,

it seems to me that you were somewhat overwhelmed, so you involuntarily "checked out" ie you weren't fully present. Happened to me (and still happens) when T and I started to talk about difficult stuff. T explained to me that this is some form of dissociation. Not talking DID here, but if you think of dissociation as some sort of continuum from simple daydreaming to DID - this is somewhere in between.

Kind of a defense mechanism when things get too difficult to handle. Trouble is that it's not always really helpful, not remembering important conversations can kind of backfire...

I know I started doing this as a kid, because I was overwhelmed, couldn't process what was going on, on an emotional but also on a cognitive level. So not registering things was probably one of the few ways I could take care of myself.

It's scary when it happens. I sometimes can't hear what people are saying, or I get a really loud beeping noise in my ears, or my eyes can't focus properly. It never lasts very long, and by now both T and I start noticing early signs so I can do something about it (like grounding exercises etc.).

Also, it happens to me when I'm in a coflict/discussion that I can't avoid. Just having someone argue against my own perspective sometimes feels so threatening, that my psyche somehow decides that it's too dangerous to stay present...

Hope you and your T manage to figure out what happened and why.
Hugs, c_r